What is involved in regular maintenance? 98 YZ400f

Sup guys,

I recently bought a 98 yz400f, and was wondering what all is good regular maintenance. What make/viscosity oil does everyone recommend? What else should i do to maintain the bike? thanks

Welcome to TT! Congrats on the 400.

First I would say change the oil often every 5-8 hours is about what I do. Change the filter every second oil change.

Air Filter clean and reoil every ride or 2 if you are lazy or it isnt dusty.

Valves check them if the bike is doing anything irregular, like being difficult to start. I would check them soon since you just got the bike and maybe once or twice a year depending on how much and how hard you ride. Service the bearings at least once a year, steering and swingarm.

Follow the manual and stay in tune here on TT if you have any questions. Do searches here for any question or repair process. Or just post. Enjoy riding it and be safe. You will learn the maintenance rituals if you stick around. O yeah always keep the carb clean. :thumbsup:

always keep the carb clean

the accelerator pump often seizes up w/ dirt/water on this carb.

Do the Taffy Mod to your AP, then use silicone to seal up BOTH ends of the little rubber accordian boot.

Seeing is it is a new bike to you I would change the brake fluid and antifreeze. I wouldn't have believed how nasty brake fluid can get in a sealed enviroment. Plus it does make a diff in braking.

Also have the fork and shock oil changed. A lot of folk dont ever look at them. They should be done yearly at least. its easy to do yourself with a few basic tools.

Lube the steering, rear brake pivot, swingarm and linkage pivots, and kickstarter pivot.

Check your brake pads and rotors for wear.

See if there is any side to side movement in the wheels indicating a bad wheel bearing.

thanks guys,

im going to do an oil change on the bike pretty soon. ive ridden it a total of about 6 hours so far and really enjoy it. im also going to read the manual and check the valves. does anyone have a good recommendation on an oil to use?

and one more question, someone had told that there is a tool that makes changing spark plugs easier.. i was wondering if this is true.. last time i changed mine i had to remove the air scoops, gas tank, and top engine mount to change it..


All you have to do is remove the two gas tank mounts, the screw that connects the shrouds to the radiators, and the rubber strap. You can buy an attachment for a socket that turns at a right angle for much easier removing.

Yamalube 4R

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